


Finding Eren

by StarryAry



Category: Finding Nemo (2003), Shingeki no Kyojin | Attack on Titan
Genre: Alternate Universe - Animals, Cannibalism, Crack, Crossover, Gay fish, Multi, Serious Crack, Sorry Not Sorry
Language: English
Status: Completed
Published: 2013-08-02
Updated: 2013-08-10
Packaged: 2017-12-22 05:21:32
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 3
Words: 3,745
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/909394
Author URL: https://archiveofourown.org/users/StarryAry/pseuds/StarryAry
Summary: <blockquote class="userstuff">
              <p>Instead of struggling to survive against Titans, everyone is a sea creature and lives life in fear of sharks.</p>
            </blockquote>





	1. A sharking discovery

**Author's Note:**

> One day I randomly thought Levi reminded me of a blowfish. Then woops, crossover.

Of all the fish, Levi was the most brash. A puffer who demanded attention from his peers without inflating. Other fish feared and admired him, because alone he could fend off more sharks than any school. 

One day, Levi and his small team of scouts were patrolling the parameter of the reef when they spotted two sharks. But something was off. The sharks were... Fighting each other? This was a rare sight. Levi and his team hid and watched. 

The smaller of the two sharks clearly had the upper hand. And the three hiding fish gasped when he landed a final, nearly lethal bite at the gills. The severely injured shark yelled through pained breath, "Crazy asshole!" before swimming away. 

"That's what happens when you try to eat my friends! " yelled the victor. Two creatures swam up to the shark. 

A yellow, shy looking octopus laid an arm across the shark's face. "Thank you Eren." it said.   
The swordfish accompanying the octopus swam up along side Eren, the shark. 

"Mikasa." Eren scolded. "I know you can handle yourself, but when I'm here there's no reason to fight." the swordfish looked the other way for a moment, before thanking Eren herself. 

Levi turned to his catfish subordinate. "Mike, am I hallucinating again, or does that shark have fish friends?" 

Mike's whiskers twitched like they often do when he is smelling the water around him. Mike just grunted. 

Hanji, a very curious cuttlefish escapes her hiding place and approaches the odd group. Levi yells after but she is much too enthralled by the thought of a friendly shark to heed his warnings. She swims up cautious, but stops only feet away, and the swordfish notices her first. 

"Can we help you? " Mikasa said plainly.

Startled, the octopus yelped, "Don't be rude Mikasa! We're the ones who need help." the octopus studied the cuttlefish, then bowed to Hanji. "Greetings fellow cephalopod. We have just swam into this area in search of refuge. Our reef to the east has been crushed by a ship that then sank, and is now overrun by sharks and is no longer safe. My name is Armin. Pleased to make your acquaintance." Armin produced an arm to Hanji. 

She briefly shook tentacles with him. "Hanji..." she replied absentmindedly, then broke the shake to swim right up to Eren. She inspected him a moment, unsure of his breed. "Fascinating. You look hungry but are making no effort to eat your companions. I have never seen a shark perform such an amazing feat." 

"Hahaha, yeah. The name's Eren. Eren Jaeger."

"Jeager... " She decides to make a leap of deduction, "great white?" 

"Yes, good catch. Not many fish can pin my breed, as I'm not as large as others."

"Eren, why do you not feed on us? " Hanji asked too eager. 

Eren shifted uncomfortably under Hanji's strong gaze and interrogation. She notices, and backs off a bit, not wanting to upset a shark regardless of the behaviour it displays. 

"One moment," Hanji pauses, "I must retrieve my corporal."

She swims back to the reef. Excited and slightly crazed with her love of predators.   
"Levi. Corporal Levi! Come! Come meet this wonderful great white." Levi and Mike come after her, much more cautious than what's polite. "Eren, this is Levi, Corporal of our Scouting Legion. Levi, Levi, they need a place to stay. We should provide them with shelter!" 

Levi approached ever so slowly. "The reef would never allow a shark, Hanji." 

Armin then swam up to Levi, "Oh, not for Eren. For the fish. There are 10 of us, Mikasa and I included that need shelter. Eren is our bodyguard."

Levi stopped 5 feet from Eren. Mike swam directly up to him, sniffed him, smirked, then swam back to Levi. "It's not my decision to make." Levi revealed, "and I am not so sure this isn't some elaborate trap."

Mikasa thrashed angerly. "He won't help us Eren, let's go." but Eren didn't budge for several seconds. Armin looked at him wearily. Then suddenly Eren snapped to attention, locking eyes with Levi. 

"CORPORAL. I, Eren Jaeger, have sworn my life to fighting Sharks! Please take my friends into your care!" Levi returned the stare. He could see the firey passion in his eyes and hear the truth in his words. 

After several seconds without blinking, the puffer fish turned to Mike the catfish. "Mike, fetch the commander. Erwin should be the one to decide."


	2. Hunger

**Notes for the Chapter:**

> Currently unbeta'd

Eren is different from any other shark. He was raised with regular fish and didn't learn he was a shark until he started to outgrow his parents. The hardest part was when people came to fear him. In his reef, there was a time when his sister Mikasa and his best friend Armin had to stick up for him when the majority of the fish he grew up with wanted him gone. It was hard emotionally for a while but soon, after they allowed him to live and stay, it got hard physically. There was never enough to keep Eren fed. Eren got sick from eating too little when Mikasa, out of frustration, killed a shark who was scouting the area for stray fish instead of scaring it off. She brought Eren to the fresh carcass, and Eren ate well for the first time he could remember.

From then on the reef counted on Eren to keep them safe, and Eren counted on the sharks attacking to keep him fed. Eren was a cannibal shark, but anything to keep him from eating his fish friends. 

***

Mike had left, and Eren excused himself so that when the Commander came he would not have to be threatened by the presence of a shark. Armin told Hanji and Levi the story of how Eren became the friendly shark they knew. 

"Where did Eren go just now? " Levi asked. 

Mikasa and Armin exchanged glances. Hanji seemed to understand. "He went after that injured shark, didn't he."

Armin nodded. 

Levi pondered the pros and cons to having a cannibal shark around. He thought the idea was extremely appealing and in ways it definitely shouldn't have been. He found himself oddly attracted to this 'friendly' shark. Although he had always been infatuated with powerful creatures. He and Hanji had that in common. 

Hanji and Armin talked amongst themselves, a conversation Mikasa and Levi barely understood. Inkfish were so much smarter than other sea creatures. They both seemed so pleased to have another intelligent being around. Mikasa stared into the distance where Eren had gone. Visibly worried. 

"The shark he went after was in terrible shape. He should be fine on his own." Levi offered.   
Mikasa glared at him, eyes full of nothingness. She made no movement except to keep herself hovering in place. She looked back out to the open ocean and said, too quiet for Levi to hear, "Lone sharks don't flee, they fight to the death." 

Commander Erwin, a large and very strong Tuna arrived, and Hanji explained the situation, leaving Eren's specie out of the report. When Hanji finished, Levi proposed that Eren join the recon corps, and they all waited for the commander's sure-to-come question: "Well then, where is this Eren?"

"He went after the shark, Sir." Hanji revealed. 

"Alone?" the Commander asked. 

"Yes Sir." she replied. 

"That's ridiculous, a fish headed out of the reef alone is sure to get eaten." the commander seemed to frown at the thought of losing a fighting companion before even meeting him. 

Levi thought it best to tell Erwin now.   
"Commander Erwin, Sir. Eren Jaeger is in fact a shark himself and from watching him fight I believe he can handle things out there."

The information soaked in a bit, and Erwin accepted the information easily. In military spirit he called to the loyal blowfish. "Levi, I trust your judgement. If Eren is indeed an asset and not a threat, I will leave him to you. Armin, Mikasa, all 11 of your survivors may stay with us. 

***

Eren followed the sent of torn shark flesh. His hunger grew as he got closer and closer to his prey. It would be an easy kill, if it hadn't died already. Not being able to use one set of gills would make it extremely difficult to survive after an attack like that.

He found the shark, alive with two others. 

Shit. Taking on three sharks at once was not something he was confident in. Especially as hungry as he was. 

Eren layed against some grey rocks so not to be seen. One shark examined the wounds, and after several minutes, the other shark left the two behind. 

Now was the time to strike. 

As soon as he believed the other shark was out of ears reach, Eren made his move. He crept slowly at first, finding a tactical point and then suddenly he flashed to the able-bodied shark. Precise biting proved to gain an upper hand, but the fight was not that easy. This shark was strong. A fighter maybe. It took a visceral bite to his tailfin for Eren to significantly handicap his opponent. Most of the shark's motor skills were shot now. Eren backed away and watched the shark thrash towards him. Tiring itself as it bled. He looked around for the previously injured shark and saw him nowhere.   
"Shit, he escaped. I'll have to take this one then." Eren looked at the pathetic mess of a predator before him and sighed. Without another thought he struk another bite to the face of his foe, killing him instantly. 

And he fed. 

Gnawing on the raw, still bleeding flesh of another shark. 

It was delicious. 

***  
Eren returned to the reef with welcome arms from Hanji and Armin. Literally. Why did Cephalopods have to be so... touchy?

"Eren!" Armin exclaimed, "the Commander said we could stay. That _you_ could stay!" Eren blinked in shock. 

"That's it? No trials? No tests to prove I can go without sushi?" Eren asked. Levi swam up and interjected. 

'No. That's not it." He stated, "You will be staying with me, and I have been ordered to keep an eye on you. If you display any suspicious activity I have the authority to kick you out." 

Eren tapped a fin to Levi. "I'm more than okay with that." 

Levi blushed. 

***

Eren, Mikasa, Armin, Hanji and Levi left the reef to get the rest of the hiding survivors. They returned with Jean--a seahorse, and several other fish, even a hermit crab by the name of Connie. 

"Eren, it was terrible." Jean whimpered on the journey to the new reef, "It was a sharknado. They got Marco. They... they got Marco." Jean started to sob. 

"We'll be safe again when we get home, Jean." Mikasa offered. It was the least she could say. Marco and Jean were inseparable. "His death was not in vein. He helped so many escape. Yourself included." 

They arrived to the reef again and each creature was provided a place to call their own. Reef Rose wasn't as large as Reef Maria, where Eren was from, but it had significantly less inhabitants so there was room to go around. 

Levi hadn't been kidding when he told Eren they were staying together. Levi lived in a coral Grove on the edge of the reef with just enough room for a Great White to sleep comfortably. "Why so much space?" Eren asked.   
"My home was the base of operations for the Scouting Legion until recently." Levi said as he shooed some krill out of the place," No shitting. I just got the place cleaned the way I like it. Go outside with your business." Eren thought that was odd, but agreed anyways. Maybe he thought big sharks made big messes. "It's getting late Jaeger, and I have patrol again in the morning. Go to sleep as you'll be joining us." 

Eren responded by simply falling asleep without saying a thing.


	3. Kill 'em Dead

**Notes for the Chapter:**

> I kinda based the relationships on the idea that fish-years are shorter than human years, so a week is like a month I guess.

Days passed. Levi and Eren made patrols around the reef together every day. They had quickly grown fond of each other,and they were known to be practically inseparable. Civilian fish were terrified of Eren's presence, though at the same time calling him the Ocean's last hope. In the week since Eren and the creatures of Reef Maria, Eren had become a pillar of the Recon Corps.

Two nights after arriving, a nurse shark had tried to get into a less populated part of the reef, but word got back to the cross quickly, and by the time Eren arrived only two fish had lost their lives to the shark. Having quite the size advantage, Eren took it out in one fell swoop. 

In perfect time too. 

Eren has started to get hungry. 

This morning had been peaceful. Eren had considered making a move to nudge their relationship into a romantic one, but he couldn't bear to ruin a good morning with being rejected. 

"Corporal Levi!" Armin called out to the outer cavern he and Eren called home. "The commander would like to see you before patrol today." Levi grunted and swam to meet the bag of arms Eren called his best friend. After getting more details, Levi took off towards Erwin's headquarters, and Armin used the opportunity to talk with his best friend. 

Armin cooed Eren's name as he clung to his back. "We all miss you!" he exclaimed. "Jean even asked Mikasa if he could come with her to the edge to see you."

Eren scoffed at him, "I think he's just looking for a date." Armin blushed at the notion, but Eren couldn't see it as Armin was still on his back. 

"Speaking of date... " Armin trailed off. When he refused to finish his sentence, Eren swam out of the cavern to tousle with his friend to get him to talk. They were a giggling mess for several minutes until Armin finally broke. 

"I'm going to ask Hanji on a date," he whispered to Eren. "She was telling me about this sea turtle who does comedy every few nights near the surface. I'm going to invite her to go with me." 

Eren smacked Armin playfully with his fin. "Lookit you, loverboy. I'd be jealous but you know, I am sleeping with a Corporal." Eren said playfully. They swam circles around each other as they shared stories. 

"By sleeping with him you mean... " Armin asked. 

Leaning in close, Eren pretended that he was going to give a juicy detail, and when he was close enough he teased, "Pla-ton-ic-ly." They laughed out loud before Eren coughed and added, "for now anyways." 

"But he's so tiny!" Armin played. "And boy are you pushing _all_ the boundaries. Size, rank, age, gender, forget order because you two aren't even the same biological class!" 

They chatted light heartedly, as friends do, but that probably wasn't the best idea, being out in the open like that.  
Mid laughter, the water became still, and Armin hushed. Eren noticed and paused as well. They sat in silence for several seconds before before Armin spoke. 

"Something's wrong." His voice barely a whisper. Eren shifted. He was right. Something was definitely off. They backed towards the safety of the coral, and Armin slunk back where he was protected by the wall the coral created. "Be careful, Eren." He nodded. A minute passed. Then two. The sounds of the ocean crept back, and the feeling of danger subsided. 

Eren turned around to face Armin. "I think the coast is clea--" 

A shark shot upwards at Eren, and another came from the left. Suddenly Eren was trapped in a net. He was being sharknapped. Testing the strength of the ropes, Eren nipped at them, and whipped around trying to free himself. He soon found it pointless. "Armin!" Eren yelled, "Don't let anyone come after me!" the last thing Eren wanted was for his friends to die in a hopeless battle to rescue him. He would escape without help. He would kill these sharks and eat their hearts. The two sharks hauled him off despite his thrashing. Eren stopped whipping his tail when the net seemed to close on him so tight it hurt. 

He looked to his left. The shark he had attacked days before. To his right, the brawny shark that he had seen with the other two earlier. 

Fuck. 

They were getting their revenge. 

***

Armin jetted through the coral, the seaweed, passed fish he knew, and ones he had yet to meet. He was quick. Before he could reach Erwin's place, he was yelling.  
"Commander Erwin! Corporal Levi! Eren has been abducted!" and thankfully he had been loud enough because several soldiers of the Legion, including Mikasa came rushing towards him. Mikasa stopped inches away from him, killing intent on her face. 

"Who." she snarled. 

"The shark that had followed us here. They're headed towards the south."

"Trost." Levi realized. Mikasa and Levi both took off, quicker than Armin knew they could swim. Mikasa could fight, sure, but Levi? Levi's only defence was making himself look twice his size, wasn't it? Neither of them could bear to lose Eren. He could tell. But Eren's specific wishes had been not to attempt a rescue. Armin followed the group, he had a tactical advantage by being able to produce an inkcloud. This could work. Assuming there were only two sharks, this could definitely work. And so they swam for Trost. 

Armin devised a plan on the way. He shared it and everyone agreed that it was much better than storming in. They stopped about 100 yards from Trost, a shipwreck famous for the human skeletons that littered the interior. The ship was hardly decayed, the water had somewhat preserved it. When the ship had nosed down so many years ago, the hull cracked in half, so it sunk in two pieces. The 50 foot space between them was currently occupied by three active sharks, and Eren, still caught in his net.

Armin, Levi, Mikasa, Reiner (a barracuda) and Bertholt (a moray eel) were the ones to rush to Eren's rescue. Reiner and Bertholt were both from Reef Maria, so Levi was the only Rose native to come, and the only non-predator. 

Before the adrenaline could wear off, they swam into action. Armin went in first, to create the inkcloud cover, and incapacitate the largest of the sharks. Reiner followed suit and went for the third shark, Bertholt attacking the one in Armin's grasp. They were quick enough to catch the sharks off guard. Mikasa went for the injured shark. She stabbed him in the eye and let him sling her off, (the easiest way to dislodge.)  
While the predators fought, Levi moved in to free Eren. The most important part of the plan was freeing Eren. 

Mikasa had bloodied the shark she took to the point where he passed out. White hot with rage she slashed at him uselessly as he was already close enough to dying to ignore. There was the stench of death in the water as Armin and Bertholt had succeed in de-finning theirs, and rushed in to help Reiner, who had taken substantial damage. The three of them all attacked in unison, and when Mikasa had enough revenge she joined them, allowing Reiner to fall back. 

The whole fight had maybe lasted two minutes. 

Levi had succeed in releasing Eren from his bonds. He lunged for the largest shark, that had sank to the sea floor, having no fins to swim with. He tore into the meat of his attacker, earning a defiant roar from the thrashing shark beneath him. Without bothering to deal any killing bites, he ate. 

He ate the shark _alive._

Now dead, the shark that had fought the hardest was at the teeth and fangs of Mikasa, Reiner and Bertholt. 

Silence reigned except for the sound of a wailing shark being eaten alive. 

"Eren." Levi called. "Eren, stop." he swam into Eren's line of sight and his heart nearly stopped when he saw just how barbaric he looked as he ate. He really was a predator. Hungerly tearing into flesh. Not a drop of remorse or hesitation in his eyes as he devoured another of his species. 

"Eren? Baby? We have to go, more sharks could come." Eren paused. He had heard Levi this time. 

He looked at the finally-dead meal before him. Then he looked back at Levi. "Levi... What... What are you doing here?" Levi explained, confused by how he's asking now, and not when he was working Eren out of the net three minutes ago. "What do you mean you came to _rescue_ me? I told Armin not to get help. Levi, Levi you could have _died_." 

"Same goes to you, Eren. I wouldn't have been able to live with myself if I had let that happen. Eren, I..." Levi inhaled a bit of water to make himself look bigger, "I love you." 

Eren stopped breathing. His entire life had been filled with fish who were too afraid to get close to him, and now, now he was _loved?_ His heart skipped a beat in his chest and he started breathing again. Levi wasn't afraid. Levi loved him. 

"We're ready!" Mikasa called. The last part of the plan was to drag the shark carcases in the net back to the reef to feed Eren and other predator fish living in the reef. They had gathered all but the one Eren had. "Let's load him up and go home." Levi suggested. He had taken Eren's unresponsive stupor as a positive response and knowing the situation did not allow time for such delicate interactions, led Eren home. 

***

They got back to the reef to be greeted by friends. Hanji welcomed Armin with welcome arms and Armin embraced her back. Jean tried to welcome Mikasa back but her lack of interest had him ebbing away, and he complained to Connie incoherently, something about his faith in the world. 

Levi and Eren made their way back home. The second they entered their little cavern, Eren took Levi in his fin. "I love you too, Levi. Thank you for coming to get me." 

"I told you, that by staying here I was responsible for you. I never go back on my word. Brat." They snuggled together for minutes, needing each other's company after the eventful morning they had just miraculously survived. 

Eren giggled and held Levi as closely as possible. "Still." He paused, and took a deep breath, "Thank you."

**Notes for the Chapter:**

> Currently eating blue shark gummies, yolo.


End file.
